With regard with the first sentence, we understand you don't want to incriminate yourself here, but don't lie to us either man.
On the second sentence, on one instance it turned out the subframe damage happened when shop installing an exhaust forgot to tighten 2 of the 3 bolts (the ones holding the brackets where exhaust hangs) holding the differential to the subframe, and eventually snapped the 3rd. Not owner's fault directly, but even less BMW's.

I'm curious to know where and why you would have to take off a bolt holding the differential to the subframe when installing an axleback exhaust?